Dental calculus and plaque are two undesirable, but unfortunately common, dental conditions experienced by the general population.
Dental caculus, or tartar as it is sometimes called, is a deposit which forms on the surfaces of the teeth at the gingival margin. Supragingival calculus appears principally in the areas near the orifices of the salivary ducts; e.g., on the lingual surfaces of the lower anterior teeth and on the buccal surfaces of the upper first and second molars, and on the distal surfaces of the posterior molars.
Mature calculus consists of an inorganic portion which is largely calcium phosphate arranged in a hydroxyapatite crystal lattice structure similar to bone, enamel and dentin. An organic portion is also present and consists of desquamated epithelial cells, leukocytes, salivary sediment, food debris and various types of microorganisms.
As the mature calculus develops, it becomes visibly white or yellowish in color unless stained or discolored by some extraneous agent. In addition to being unsightly and undesirable from an aesthetic standpoint, the mature caculus deposits are constant sources of irritation of the gingiva.
Another source of irritation in the oral cavity is plaque. Plaque is a combination of minerals and bacteria found in the mouth. The bacteria associated with plaque can secrete enzymes and endotoxins which can irritate the gums and cause an inflammatory ginigivitis. As the gums become increasingly irritated by this process, they have a tendency to bleed, lose their toughness and resiliency, and separate from the teeth, leaving periodontal pockets in which debris, secretions, more bacteria and toxins further accumulate. It is also possible for food to accumulate in these pockets, thereby providing nourishment for increased growth of bacteria and production of endotoxins and destructive enzymes.
Mechanical removal of calculus periodically by the dentist is, of course, routine dental office procedure. However, effective compositions and methods for inhibiting calculus formation between dental office visits are desirable for enhancing oral hygiene. A wide variety of chemical agents have been suggested in the art to retard calculus formation or to remove calculus after it is formed.
Inhibiting the formation of calculus between dentist visits has generally been accomplished with chemicals that involve chelation of calcium ion and/or crystal growth inhibition which prevents the calculus from forming and/or breaks down mature calculus by removing calcium.
The art discloses a number of chelating agents for this purpose. British Pat. No. 490,384, Feb. 15, 1937, discloses oral compositions containing ethylenediaminetetraacetic acid, nitrilotriacetic acid and related compounds as anticalculus agents. These anticalculus agents have relatively low effectiveness.
Also disclosed in the art are oral care compositions containing soluble pyrophosphate salts. Included among such disclosures are U.S. Pat. No. 2,941,926, June 21, 1960 to Salzmann et al. which discloses dental powders containing chlorophyll and pyrophosphate salts; U.S. Pat. No. 3,137,632, June 16, 1964 to Schiraldi, which discloses toothpastes containing pyrophosphate salts; U.S. Pat. No. 3,927,201 and 3,297,202, Dec. 16, 1975 to Baines et al. and Harvey et al., respectively, which disclose toothpastes which utilize soluble pyrophosphates as abrasives; U.S. Pat. No. 4,244,931, Jan. 13, 1981, and U.S. Pat. No. 4,247,526, Jan. 27, 1981 to Jarvis et al., which disclose pyrophosphate salts in dicalcium phosphate systems; Japanese Patent Application Disclosure No. 4945-1974, which discloses soluble pyrophosphates in a variety of dentifrice systems; U.S. Pat. No. 4,333,551, Apr. 6, 1982 to Parran, which discloses tetraalkali metal salts in mouthwash compositions; U.S. Pat. No. 4,515,772, May 7, 1985, to Parran et al., U.S. Pat. No. 4,590,066, May 20, 1986 to Parran et al., and U.S. Pat. No. 4,684,518, Aug. 4, 1987 to Parran et al., which disclose toothpaste compositions containing particular dialkali metal and tetraalkali metal pyrophosphate salts.
Mechanical removal of plaque and the minerals found which can collect near or underneath the gums which nourishes the bacteria which causes plaque is accomplished by conscientious oral care practitioners by brushing and flossing after meals. Mechanical removal, unfortunately, is not always completely thorough or effective, especially when not performed correctly and regularly. It is desirable to provide chemical compositions and methods which effectively inhibit plaque formation. These are preferably used in combination with mechanical methods of removal.
The art contains numerous disclosures of phosphonate materials useful as both anticalculus and antiplaque/antigingivitis agents in oral compositions. For example, U.S. Pat. No. 3,429,963, issued Feb. 25, 1969 to Shedlovsky, U.S. Pat. No. 4,102,993, issued July 25, 1978 to Gaffer, U.S. Pat. No. 4,042,679, issued Aug. 16, 1977 to Gaffer, U.S. Pat. No. 4,100,270, issued July 11, 1978 to Gaffer, U.S. Pat. No. 4,098,880, issued July 4, 1978 to Gaffer, U.S. Pat. No. 4,123,512, issued Oct. 31, 1978 to Gaffer, U.S. Pat. No. 4,138,477, issued Feb. 6, 1979 to Gaffer, and U.K. patent application No. 2,151,478, published July 24, 1985, Gaffer, all disclose polyvinyl phosphonate polymers having monophosphonate monomeric units. U.S. Pat. No. 3,553,315, issued Jan. 5, 1971 to Francis, discloses short chain carboxyphosphonic acid compounds. U.S. Pat. No. 3,553,314, issued Jan. 5, 1971 to Francis, U.S. Pat. No. 3,641,126, issued Feb. 8, 1972 to Prentice, and U.S. Pat. No. 3,737,522, issued June 5, 1973 to Francis, disclose nonpolymeric compounds having geminal diphosphonate groups.
U.S. Pat. No. 4,208,401, issued June 17, 1980 to Bauman, discloses a quaternary ammonium alkylene diphosphonate anticalculus agent having a geminal diphosphonate carbon. U.S. Pat. No. 3,678,154, issued July 18, 1972 to Widder et al., and U.S. Pat. No. 4,025,616, issued May 24, 1977 to Haefele, disclose polyphosphonate materials having one phosphonate group per carbon in the polymer backbone and phosphonate molecules having one geminal diphosphonate carbon atom.
While numerous materials as described above have been disclosed for use in oral compositions as anticalculus and antiplaque agents, there still exists a need for improved anticalculus and antiplaque agents.
It is an object of this invention to provide safe and effective anticalculus oral care compositions having good long term storage stability and high effectiveness.
It is a further object of this invention to provide oral care compositions, as described above, that provide both anticalculus activity and antiplaque activity.
It is another object of this invention to provide safe and effective anticalculus and antiplaque oral care compositions which, in addition to being stable and having high anticalculus and/or antiplaque effectiveness, can be made at commercially viable economic cost.
It is yet another object of this invention to provide a safe and effective method for inhibiting the formation of calculus and in the oral cavity. It is still another object of this invention to provide a safe and effective method for inhibiting the formation of both calculus and plaque in the oral cavity.
It is still a further object of this invention to provide a safe and effective method for inhibiting the formation of calculus and/or plaque which, in addition to providing anticalculus and antiplaque efficacy, can be implemented at commercially viable economic cost.